/Engine/Source/Runtime/Engine/Classes/GameFramework/CharacterMovementComponent.h
Determines whether to use packed movement RPCs with variable length payloads, or legacy code which has multiple functions required for different situations. The default implementation checks the console variable "p.NetUsePackedMovementRPCs" and returns true if it is non-zero.
virtual bool ShouldUsePackedMovementRPCs() const